A Phenome-Wide Mendelian Randomization and Colocalization Study Reveals Genetic Association Between PBC and Other...

Area of Science:

• Genetics
• Immunology
• Endocrinology

Background:

• Primary biliary cholangitis (PBC) is a chronic autoimmune liver disease often co-occurring with other autoimmune conditions.
• Understanding the genetic links between PBC and other autoimmune disorders is crucial for comprehensive patient care.

Purpose of the Study:

• To investigate the genetic associations and causal relationships between primary biliary cholangitis (PBC) and other diseases, particularly autoimmune disorders.
• To identify potential therapeutic targets for hypothyroidism based on genetic associations with PBC.

Main Methods:

• Phenome-wide association study (PheWAS) and Mendelian randomization (MR-PheWAS) were employed using UK Biobank data.
• Bidirectional two-sample Mendelian randomization and colocalization analysis were conducted to confirm causal links and identify shared genetic variants with hypothyroidism.
• Enrichment analysis of 35 PBC risk loci was performed.

Main Results:

• Genetic liability for PBC was associated with an increased risk of 25 traits, including hypothyroidism, asthma, and multiple sclerosis.
• A significant causal association was confirmed between PBC and hypothyroidism in both directions.
• CCDC88B and MMEL1 were identified as genes positively associated with hypothyroidism risk and potential drug targets.

Conclusions:

• Phenome-wide Mendelian randomization demonstrates a significant genetic association between primary biliary cholangitis and hypothyroidism.
• The study identified CCDC88B and MMEL1 as potential therapeutic targets for hypothyroidism, offering new avenues for treatment development.